Transfer switch with movable contact toggle mechanism for tapped regulating transformers



June 28, 1966 A. BLEIBTREU 3,258,546

TRANSFER SWITCH WITH MOVABLE CONTACT TOGGLE MECHANISM FOR TAPPED REGULATING TRANSFORMERS 4 Sheets-Sheet 1 Filed Jan. 51, 1964 INVENTOR ALEXANDER BLEIBTREU, Mm 3W ATTORNEY J1me 1966 A. BLEIBTREU 3,258,546

TRANSFER SWITCH WITH MOVABLE CONTACT TOGGLE MECHANISM FOR TAPPED REGULATING TRANSFORMERS Filed Jan. 31, 1964 4 Sheets-Sheet 2 INVENTOR= ALEXANDER BLEIBTREU,

BY Y X'I'TORNEY June 28, 1966 A. BLEIBTREU 3,258,546

TRANSFER SWITCH WITH MOVABLE CONTACT TOGGLE MECHANISM FOR TAPPED REGULATING TRANSFORMERS Filed Jan. 31, 1964 4 Sheets-Sheet 3 INVENTOR= ALEXANDER BLEIBTREU,

BY ATTORNEY J 1966 A. BLEIBTREU 3,258,546

TRANSFER SWITCH WITH MOVABLE CONTACT TOGGLE MECHANISM FOR TAPPED REGULATING TRANSFORMERS Filed Jan. 31 1964 4 Sheets-Sheet 4 INVENTOR= ALEXANDER BLEIBTREU,

United States Patent 55,73 21 Claims. (Cl. 200-6) This invention has reference to transfer switches for tap-changing regulating transformers, and more particularly to transfer switches for transformers known as J ansen type transformers. In such transfer switches changes from one limit position to another limit position are effected very rapidly, and auxiliary contacts insert ohmic switch-over resistors into the circuit in positions intermediate the limit positions of the transfer switches.

In transfer switches of the aforementioned description arcing is a serious problem frequently requiring the application of arc-quenching structures such as, for instance, are chutes.

It is, therefore, one object of this invention to provide transfer switches of the aforementioned description wherein arcing is minimized without the presence of arc-quenching structures, or wherein arcing is minimized in the presence of arc-quenching structures which are more compact, and less expensive to manufacture, than the arc-quenching structures heretofore required under comparable conditions.

Another object of this invention is to provide transfer switches of the aforementioned description wherein the opening speed characteristic of each movable contact can readily and individually be determined at will, thus minimizing the degree of arcing, or arcing time, which occurs on separation of cooperating separable contacts.

In conventional transfer switches for Jansen type transformers, or Jansen type transfer switches, the cooperating contacts are not as readily accessible as may be desired, or not sufiiciently readily accessible. This tends to make inspection, maintenance and repair of such switches a relatively difficult and onerous task.

It is, therefore, another object of this invention to provide improved Jansen type transfer switches wherein the cooperating contacts are more readily accessible, thus greatly simplifying inspection, maintenance and repair of such switches.

United States Patents 2,680,790 issued June 8, 1954, and 2,833,873 issued May 6, 1958, to Bernhard Jansen titled, respectively, Load Change Over Switch for Tapped Transformers Using a Combination of Contact Movements, and Multi-Pole Tap Switch Construction for Changing Transformer Taps Under Load, are concerned with transfer switches wherein the fixed contacts pertaining to each phase of a three phase circuit are arranged in form of an are or of a sector of about 120 degrees inside of a cylindrical contact support of insulating material, and wherein the movable contacts have off-positions whose spacing from the axis of said cylindrical contact support is smaller than that of the fixed contacts, and wherein the movable contacts are associated with contact-operating means imparting to the movable contacts radially outward movements to cause them to engage their cooperating fixed contacts.

In transfer switches having such an arrangement of the fixed and of the movable contacts both the fixed contacts and the movable contacts are relatively inaccessible and therefore difficult to inspect and to maintain and repair.

It is, therefore, another object of this invention to provide transfer switches capable of performing substantially the same switching operations as the transfer switches dis- Patented June 28, 1966 closed in the two aforementioned patents to Jansen, but having cooperating fixed and movable contacts which are more readily accessible than those of the aforementioned prior art transfer switches.

While this invention is primarily intended for polyphase, or three-phase, transfer switches, the invention is equally applicable to single-phase transfer switches as will be fully apparent from the ensuing description of a specific embodiment of the invention when considered in conjunction with the appended drawings.

Referring now to the drawings:

FIG. 1 is a diagrammatic perspective view of the contact structure of a polyphase or three-phase transfer switch embodying the present invention showing the fixed contacts and the movable contacts of but one single phase thereof, the contacts of the other phases being omitted in FIG. 1;

FIG. 2 is a vertical section of a polyphase or three-phase transfer switch embodying the present invention taken substantially along 2-2 of FIG. 3;

FIG. 3 is a top plan view of the structure of FIG. 2;

FIG. 4 is a portion of a section taken along 44 of FIG. 2 drawn on a larger scale than FIG. 2 and limited to the constituent parts of one phase of the transfer switch, the constituent parts of the two other phases being omitted in FIG. 4;

FIG. 5 is a side elevation of a detail of the structure of FIG. 2 seen in the direction of the arrow A in FIG. 2;

FIG. 6 is a diagram illustrating the method of control of the speed of the movable contacts of the structure of FIGS. 1-4 by means of cams; and

FIG. 7 is another such diagram.

Referring now to the drawings, and more particularly to FIGS. 1-4 thereof, reference character Tr has been applied to indicate a transformer winding having two spaced taps U and U The fixed contacts of the transfer switch are supported by a pair of spaced coaxial cylindrical structures 6, 7 of insulating material held in spaced relation by three vertical spacing bars or rails 8, angularly displaced degrees. One-third of the outer surfaces of cylindrical insulating structures 6, 7 supports the fixed contacts 2, 3, 4, 5 of phase U, the fixed contacts of this phase being shown in FIG. 1. The fixed contacts of the two other phases V, W supported by the two other thirds of the outer surfaces of parts 6, 7 have been omitted in FIG. 1. Each insulating cylinder 6, 7 supports one of a pair of spaced fixed contacts which are arranged in registry and adapted to be conductively interconnected by a movable contact or contact bridge. Thus fixed contacts 2, 2 are arranged in registry and adapted to be conductively interconnected by movable contact bridge 9. The same applies in regard to fixed contacts 3, 3 and contact bridge 10, in regard to fixed contacts 4, 4 and contact bridge 11, and in regard to fixed cont-acts 5, 5 and contact bridge 12. Fixed contacts 2, 2 and 3, 3 are main contacts and the intermediate fixed contacts 4, 4 and 5, 5 are auxiliary contacts. Contact bridges 9, 10 are main contacts and contact bridges 11, 12 are auxiliary contacts. Leads L L conductively connect taps U and U to the lower fixed main contacts 2, 3. Leads L L conductively connect taps U and U by intermediary of resistors R to the lower fixed auxiliary contacts 4, 5. All the upper fixed contacts 2, 3, 4, 5 are grounded by a system of leads L this being the case when considering a Y connected regulating transformer whose neutral point is grounded.

In the position of the transfer switch shown in FIG. 1 contacts 2, 9, 2 are in engagement and contacts 4, 11, 4; 5, 12, 5 and 3, 10, 3 are out of engagement. Hence tap U is connected into the circuit and tap U is not included into the circuit. Changing from tap U, to tap U involves the following operations to be performed in the following sequence:

Contact bridge 11 engages fixed contacts 4, 4. Contact bridge 9 parts from fixed contacts 2, 2. Contact bridge 12 engagesfixed contacts 5, 5. Contact bridge 11 parts from fixed contacts 4, 4. Contact bridge engages fixed contacts 3, 3. Contact bridge 12 parts from fixed contacts 5, 5.

The above contact closing and contact opening operations involve radially inward and radially outward motions of contact bridges 9-12. The speed at which these motions are performed is of crucial importance in regard to the effectiveness of the transfer switch.

Referring now to FIGS. 2-5, inclusive, reference numeral 1 has been applied to designate a pivotable driving shaft coextensive with the geometrical axis of the insulating cylinders 6, 7 supporting the pairs of fixed main contacts 2, 2 and 3, 3 and the pairs of fixed auxiliary con tacts 4, 4 and 5, 5. Shaft 1 may be driven by motor means (not shown) as is well known in the art. Shaft 1 may be driven, for instance, by a spring motor (not shown) which may be wound-up manually. Shaft 1 is associated with motor means causing the shaft to pivot in clockwise or counterclockwise direction, depending upon whether it is desired to change from tap U to tap U or to change from tap U to tap U (see FIG. 1). If it is desired to change from tap U to tap U rather than from tap U to tap U the direction of the pivotal movement of shaft 1 is reversed. This reverses the above sequence of engagement and disengagement of contacts as will be more apparent from the following detailed description of the drive of contact bridges 9-12.

Reference numerals 14, have been applied to indicate a pair of substantially disc-shaped, spaced, parallel structures arranged at right angles to driving shaft 1. Disc-shaped structures 14, 15 are supported by the spacers 8 for insulating cylinders 6 and 7, as clearly shown on the right of FIG. 2. Disc-shaped structures 14, 15 define cam slots 16 each adapted to form a guiding means for a pin, or the like, entering into it. Disc-shaped structure 17 is arranged below of and parallel to disc-shaped structure 14 and defines cam slots 16 in registry with the cam slots 16 defined by disc-shaped structure 14. Disc-shaped structure 18 is arranged above and parallel to disc-shaped structure 15 and defines cam slots 16 in registry with the cam slots 16 defined by disc-shaped structure 15. The disc-shaped structures 14, 15 define at the outer periphery thereof radially inward extending recesses alternating in U-shape and in V-shape. Reference numerals 13 have been applied to indicate the former and reference numerals 13' have been applied to indicate the latter. Each of U-shaped recesses 13 is provided with a pair of radially extending guide surfaces or ways 9a, 10a, 11a and 12a for the contact bridges 9, 1t), 11 and 12. Registering pairs of guide surfaces or ways on upper and lower disc-shaped members 14, 15 determine the radial trajectories of the upper ends and the lower ends of contact bridges 9, 1t), 11 and 12.

Shaft 1 supports a slide-supporting member 19 arranged at right angles to shaft 1 and jointly pivotable with shaft 1. Slide-supporting member 19 has a radially inner hub portion 19a mounted on shaft 1 and a radially outer substantially fork-shaped portion 19b for each phase of the transfer switch. Slide-supporting member 19 is not shown in FIG. 3, and FIG. 4 shows but that portion of slidesupporting member 19 pertaining to one phase of the transfer switch, the other portions of member 19 being broken away in FIG. 4. Each of the fork-shaped portions of slide-supporting member 19 forms a pair of straight parallel guide surfaces or ways 26 guiding a transverse slide 25. Reference numeral has been applied to indicate a plurality of helical slide-biasing tension springs. Springs 20 interconnect the hub-portion 19a of slide-support 19 and transverse slide 25, thus biasing the latter radially inwardly toward shaft 1. Each contact bridge 9, 10, 11

and 12 is operated by a pair of linkages or toggle-levers 22, 23. One end of each pair of linkages or toggle-levers 22, 23 is pivotably secured to transverse slide 25, and the opposite end of each pair of linkages or toggle-levers 22, 23 is pivotally secured to one of the contact bridges 9, 1t 11 and 12. Each of the contact bridges 9, 10, 11 and 12 is operated from transverse slide 25 by the intermediary of an upper linkage 22, 23 arranged in planes situated be tween parts 14 and 17 and by the intermediary of a lower linkage 22, 23 arranged in planes situated between parts 15 and 18. This arrangement of linkages or toggles 22, 23 is clearly shown in FIG. 2. Each linkage or toggle 22, 23 comprises a pair of levers 22 and 23 which are pivotally interconnected at the juxtaposed end thereof by pins 24 projecting transversely through both levers 22 and 23. The ends of pins 24 extend beyond levers 22 and 23 and project into the cam slots 16. The ends of the upper pins 24 project into the cam slots 16 defined by disc-shaped structures 14 and 17 and the ends of the lower pins 24 project into the cam slots defined by disc-shaped structures 15 and 18.

The shape or geometrical configuration of cam slots 16 in parts 14, 15, 17 and 18 determines the opening speeds and the closing speeds of contact bridges 9, 10, 11 and 12 as well as the stroke versus time or travel characteristics thereof. All that is required if it is desired to alter these speeds, or characteristics, is to substitute similar parts for parts 14, 15, 17 and 18, which similar parts have cam slots 16 whose shape or geometrical configuration is diiferent and adapted to achieve the desired contact speeds and stroke versus time or travel characteristics. This will be explained below more in detail in connection with FIGS. 6 and 7.

The operation of the transfer switch shown in FIGS. l-5 and described above is as follows:

In the position of parts shown in FIG. 4 contact bridges 9, 11 and 12 are out of engagement with the cooperating fixed contacts 2, 2; 4, 4 and 5, 5 thereof and contact bridge 10 is in engagement with its cooperating fixed contacts 3, 3. Assuming that shaft 1, slide-supporting mem 'ber 19 and slide 25 are jointly pivoted in counterclockwise direction, as seen in FIG. 4. As a result, slide 25 acts on toggles 22, 23 simultaneously moving radially inwardly along spaced guide surfaces or ways 26. As the clockwise pivotal motion of parts 19 and 25 continues, pins 24 are caused to move from right to left in their respective angularly displaced cam slots 16 and simultaneously contact bridges 9, 10, 11 and 12 are caused to perform their required radial travel in the prescribed particular sequence. To be more specific, upon counterclockwise movement of parts 1, 19 and 25 the reverse sequence of operations is performed as described above in connection with FIG. 1.

Jansen type regulating transformers with load tap changers include selector switches and transfer switches. The selector switches serve the purpose of selecting a partrcular tap on a tapped transformer winding intended to be connected into an electric circuit. Selector switches do not carry any load currents at the time a particular tap is selected, i.e. they are not required to interrupt or close on current-carrying circuits. This task is performed by the transfer switches. The latter perform all switching operations under load and, therefore, only the transfer switches call for the provision of means for are control and/ or arc suppression.

In FIG. 1 no selector switch has been shown in order to limit this drawing to what is essential for an understandmg of the instant transfer switch. Normally a selector switch would be interposed between the tapped winding Tr of FIG. 1 and the transfer switch structure shown therein. FIGS. 2-5,v inclusive, have been strictly limited to the transfer switch structure according to this invention, 1.e. they do not.comprise any elements pertaining to a selector switch cooperating with the transfer switch embodying this invention.

While the driving means, or the motor means, for operating shaft 1 may be of a conventional nature, they must be sufficiently fast to drastically limit the periods of time during which the current-limiting switch-over resistors R shown in FIG. 1 must carry load or overload currents. These periods of time may be in the order of a few hundredths of a second.

The structure shown in FIGS. 1-5, inclusive, is particularly desirable because the presence of movable contact bridges and the association with each contact bridge of a pair of fixed contacts results in the formation of serially related points of break. The invention is, however, not limited to this particular feature. In instances in which it is not necessary to form serially related points of break one of the fixed contacts associated with each contact bridge may be omitted and each contact bridge may be reduced to a movable one-point-of-break contact.

The feature of arranging the fixed contacts nearer to the vertical axis of the transfer switch than the movable contact bridges and of controlling the contact bridges in such a way that they move during the closing operation thereof radially inwardly toward, and during the opening operation thereof radially outwardly away from, the fixed contacts of the transfer switch is of crucial importance in regard to inspection, maintenance and repair since this feature gives ready access to all the contacts and to the engaging contact surfaces of all thecontacts.

The embodiment of the invention illustrated in FIGS. 1-5, inclusive, and described above, is a so-called PEN- NANT transfer switch, this term for designating this type of transfer having been coined by Bernhard Jansen to whom the development of the family of so-called Jansen type transfer switches is due. Other members of this family may differ from a PENNANT transfer switch by the sequence of operation of the movable contacts or contact bridges. The number of fixed and movable contacts varies also with the number of the phases for which any particular piece of equipment is designed. The transfer switch'illustrated in FIG. 3 is intended to control a threephase circuit and comprises four movable contact bridges and eight fixed contacts per phase. This invention is not limited to any particular kind of Jansen type transfer switches, nor to any given number of phases. For information on other types of Jansen transfer switches than PENNANT transfer switches such as FLAG and FLAG PENNANT transfer switches reference may be had to the copending patent application of Alexander Bleibtreu, Ser. No. 255,291, filed January 31, 1963, now US. Patent 3,174,097 for Transfer Switch for Tap Changers for Regulating Transformers.

In FIG. 6 the same reference characters have been applied to indicate like parts as in FIGS. l5. Thus numeral 1 has been applied to diagrammatically indicate a driving shaft for operating a toggle 22, 23. Toggle 22, 23 is tied to and operates movable contact bridge 9 adapted to engage cooperating fixed contacts 2 and to be moved radially outward from fixed contacts 2 to its off position. The letter S has been applied to indicate the maximum separation of contact bridge 9 from contacts 2. Contact bridge 9 is fully moved out of engagement with contacts 2, or fully moved into engagement with contacts 2, upon shaft 1 having completed a pivotal motion encompassing the angle cc. Reference characters 16a and 16b have been applied to two different cam means each adapted to guide the center pivot 24 of toggle 22, 23 during the closing movement and during the opening movement of contact bridge 9 more fully described in connection with FIGS. 1-5. The law of motion to which movable contact bridge 9 is subject depends upon the shape, or geometry, of the cam means which guide center pivot 24. Since the shape, or geometry, of cam means 16a and 16b is different, either of both cam means 16a and 16b subjects center pivot 24 .of toggle 22, 23 and movable contact bridge 9 to different laws of motion.

These two different laws of motion have been illustrated in FIG. 7 showing the separation of contacts 2 and con- 'tact bridge 9 plotted against time.

In FIG. 7 reference character a has been applied to indicate the time-contactseparation characteristic which obtains in the case that center pivot 24 is guided by cam means 16a and reference character b has been applied to indicate the time-contactseparation characteristic which obtains in case that center pivot 24 is guided by cam means 16b. It is apparent from FIG. 7 that the use of cam means 16b results in a relatively large initial velocity of contact separation and a relatively small final velocity of contact separation. FIG. 7 further shows that the use of cam means 16a results in a relatively small initial velocity of contact separation and a relatively large final velocity of contact separation. (The velocity of contact separation is expressed by the rate of rise of curves a and b.) FIG. 7 includes additional data characterizing the performance of the same transfer switch with different cam means 16a and 1612. In a case involving cam means 16a the electric are between the separated contacts 2, 9 was extinguished upon reaching contact separation Sa. The arcing time in that particular instance was t,,. In another case involving cam means 16b the electric are between the separated contacts 2, 9 was extinguished after contact separation Sb had been reached. Therefore, in that instance, the arcing time was t Reference character t has been applied to indicate the maximum permissible arc duration or arcing time in that particular instance. It is apparent that t and that Hence cam means 16a is not suitable for the particular case in hand, but cam means 16b complies with the condition that the arcing time be less than t In any particular instance the required, or most desirable, time-contact-separation characteristic depends upon various parameters, including the intensity of the current to be interrupted, and the rate of rise of the transient recovery voltage tending to re-kindle the are which had been extinguished between the separated contacts. The kind of structure which has been described above is sulficiently flexible to comply with any time-contact-separation characteristic which may be required, or desired, in any particular case since it allows to vary time-contactseparation characteristics at will merely by changing the cam means controlling the movement of the center pivot 24 of toggle 22, 2 3.

It will be understood that although but one embodiment of the invention has been illustrated and described in detail, the invention is not limited thereto. It will also be understood that the structure illustrated may be modified without departing from the spirit and scope of the invention as set forth in the accompanying claims.

I claim as my invention:

1. A transfer switch for tapped regulating transformers comprising in combination:

(a) a plurality of fixed contacts arranged in an arcuate pattern, said plurality of fixed contacts including two fixed outer main contacts and fixed inner auxiliary contacts arranged between said two fixed outer main contacts;

(b) a plurality of movable contacts each movable along a radius of said arcuate pattern into engagement and out of engagement with one of said plurality of fixed contacts, said plurality of movable contacts including two movable outer main contacts each cooperatively related to one of said two fixed outer main contacts, and said plurality of movable contacts further including movable inner auxiliary contacts each operatively related to one of said fixed inner auxiliary contacts;

(c) a plurality of toggle-levers each having one end pivotally connected to one of said plurality of movable contacts and each including an intermediate pivot pin situated between the ends thereof; 4. A transfer switch for tapped regulating transformers (d) common means for operating the other end of each comprising in combination:

of said plurality of toggle-levers, said operating (a) a plurality of fixed contacts arranged in an arcuate means including a pivotable driving shaft arranged pattern, said plurality of fixed contacts including two in the center of said arcuate pattern and at right fixed outer main contacts and fixed inner auxiliary angles to the plane defined by said pattern; and contacts arranged between said two fixed outer main (e) a plurality of fixed cam means each cooperatively contacts;

engaging and guiding said intermediate pivot pin of (b) a plurality of movable contacts each cooperatively one of said plurality of toggle-levers. related to one of said plurality of fixed contacts;

2. A transfer switch for tapped regulating transformers 10 (c) a plurality of fixed guide means each for one of comprising in combination: said plurality of movable contacts each extending (a) a plurality of fixed contacts arranged in an arcuatc radially outwardly from one of said plurality of fixed pattern, said plurality of fixed contacts including two contacts; fixed outer main contacts and fixed auxiliary con- ((1) a plurality of toggle-levers each having one end tacts arranged between said two fixed outer main pivotally connected to one of said plurality of movcontacts; able contacts and each including an intermediate (b) a plurality of movable contacts each movable along pivot pin situated between the ends thereof;

a radius of said arcuate pattern into engagement and (e) common operating means for the other end of each out of engagement with one of said plurality of fixed of said plurality of toggle-levers, said operating contacts, said plurality of movable contacts including means including a pivotable driving shaft arranged two movable outer main contacts each cooperatively in the center of said arcuate pattern and at right anrelated to one of said two fixed outer main contacts, gles to the plane defined by said pattern, a slide-supand said plurality of movable contacts further includporting member driven by said shaft, a slide pivotally ing movable inner auxiliary contacts each operatively connected to said other end of each of said pluralrelated to one of said fixed inner auxiliary contacts; ity of toggle-levers, said slide being supported by (c) a plurality of toggle-levers each having one end and radially movable relative to said slide-supporting pivotally connected to one of said plurality of rnovmember, and a plurality of helical springs biasing able contacts and each including an intermediate said slide for radial movement relative to said slidepivot pin situated between the ends thereof; supporting member; and (d) means for operating the other end of each of said (f) a fixed structure defining a plurality of cam slots plurality of toggle-levers to operate said plurality of each cooperatively engaging and guiding said intermovable contacts, said operating means including a mediate pivot pin on one of said plurality of togglepivotable driving shaft arranged in the center of said levers. arcuate pattern at right angles to the plane defined 5. transfer switch for tapped regulating transformers by said pattern, and said driving means further incomprising in combination: eluding a spring biased radially movable member (a) a cylindrical structure substantially of insulating pivotable by and jointly with said driving shaft and material; supporting said other end of each of said plurality E} plurality of fixed contacts supported by said of toggle-levers; and cylindrical structure arranged at the same level along (e) a fixed frame structure defining a radial guide a segment thereof, said plurality of contacts includmeans for each of said plurality of movable coning two fixed outer main contacts and fixed inner tacts, said fixed frame structure further defining a auXiliary contacts arranged between aid two fi d plurality of cam slots each cooperatively engaging Outer main contacts; and guiding said intermediate pivot pin of one of (c) a plurality of movable contacts each cooperatively aid plurality of toggle-levers, related to one of said plurality of fixed contacts; 3. A transfer switch for tapped regulating transformers (d) a plurality of toggle-levers each having one end comprising i bi i pivotally connected to one of said plurality of mov- (a) a plurality of fixed contacts arranged in an arcuate able contacts and each lncluding an intermediate pattern, said plurality of fixed contacts including two p1v0t pin situated between the ends thereof; fixed outer main contacts and fixed inner auxiliary (6) common means for operating the other end of each contacts arranged between said two fixed outer main 0f aid plurality of toggle-levers, said operating contacts; means including a pivotable driving shaft coextensive (b) a plurality of movable contacts each cooperatively th the aXis Of said cylindrical structure and a comrelated to one of said plurality of fixed contacts; 111011 pp j P Y PP Sald other efldof (c) a plurality of fixed guide means each for one of eaflh 0f a f p rallty of toggle-levers and being said plurality of movable contacts, each of said pludriv n by said shaft; and rality of guide means extending radially outwardly a pl r lity of fixed cam means each cooperafrom one of said plurality of fixed contacts; Y y engaging a g f g Sald lntel'medlate P (d) a plurality of toggle-levers each having one end P Of One of sa1d plurahty of toggle-levers.

i t ll connected to one f id l lit f 6. transfer switch for tapped regulating transformers able contacts and each including an intermediate compflslng n natl ni pivot i i d between h d th f; (a) a cylindrical structure substantially of insulating (e) common operating means for the other end of material;

each of said plurality of toggle-levers, said operating (b) a plurality of fixed contacts supported by said means including a pivotable driving shaft arranged (35 cylindrical structure arranged at the same level along in the center of said arcuate pattern and at right a segment thereof, said plurality of contacts includangles to the plane defined by said pattern, and said ing two fixed outer main contacts and fixed inner operating means further including a spring-biased auxiliary contacts arranged between said two fixed common support for said other end of each of said outer main contacts; plurality of toggle-levers driven by said driving shaft (c) a plurality of fixed guide means each for one of and radially movable relative to said driving shaft; said plurality of movable contacts each extending and radially outward from the radially outer surface of (f) a plurality of fixed cam means each cooperatively said cylindrical structure;

engaging and guiding said intermediate pivot pin (d) a plurality of toggle-levers each having one end of one of said plurality of toggle-levers. pivotally connected to one of said plurality of movable contacts and each including an intermediate pivot pin situated between the ends thereof;

(e) common means for operating the other end of each of said plurality of toggle-levers, said operating means including a pivotable driving shaft coextensive with the axis of said cylndrical structure and a common support pivotally supporting said other end of each of said plurality of toggle-levers and being driven by said shaft; and

(f) a plate defining a plurality of cam slots each cooperatively engaging and guiding said intermediate pivot pin of one of said plurality of toggle-levers.

7. A transfer switch for tapped regulating transformers comprising in combination:

(a) a plurality of fixed contacts arranged in an arcuate pattern, said plurality of fixed contacts including two fixed outer main contacts and fixed inner auxiliary contacts'arranged between said two fixed outer main contacts;

(b) a plurality of movable contacts each guided along a radius of said arcuate pattern into engagement with and out of engagement from one of said plurality of fixed contacts;

(c) operating means for said plurality of movable contacts including a pivotable driving shaft arranged in the center of said arcuate pattern at right angles to the plane defined by said pattern, said operating means further including a plurality of linkages each having one end operated by said shaft and another end pivotally connected to and operating one of said plurality of movable contacts; and

(d) a fixed plate structure arranged at right angles to said shaft and defining a plurality of angularly displaced cam slots, each of said plurality of cam slots being cooperatively engaged by and guiding one point of one of said plurality of linkages intermediate said one end and said other end thereof.

8. A transfer switch for tapped regulating transformers comprising in combination:

(a) a plurality of fixed contacts arranged in an arcuate pattern, said plurality of fixed contacts including two fixed outer main contacts and fixed inner auxiliary contacts arranged between said two fixed outer main contacts;

(b) a plurality of movable contacts each cooperatively related to one of said plurality of fixed contacts; (c) a plurality of fixed guide means each for one of said plurality of movable contacts and each extend ing radially outward from one of said plurality of fixed contacts;

((1) operating means for said plurality of movable contacts including a pivotable driving shaft arranged in the center of said arcuate pattern at right angles to the plane defined by said pattern, a slide-supporting member driven by said shaft, a slide supported by and radially movable relative to said slide-supporting member, spring means biasing said slide for radial movement relative to said slide-supporting member, and a plurality of linkages each having one end pivotally secured to said slide and another end pivotally secured to one of said plurality of movable contacts; and

(e) a fixed plate structure arranged at right angles to said shaft and defining a plurality of cam slots, each of said plurality of cam slots being cooperatively engaged by a pivot pin on one of said plurality of linkages situated intermediate said one end and said other end thereof.

9. A transfer switch as specified in claim 8 wherein said plurality of fixed contacts are supported by a cylindrical structure substantially of insulating material.

10. A transfer switch as specified in claim 8 wherein saidplurality of fixed guide means and said fixed plate structure are an integral part.

11. A transfer switch for tapped regulating transformers comprising in combination:

(a) a plurality of fixed contacts arranged in an arcuate pattern, said plurality of fixed contacts including two fixed outer main contacts and fixed inner auxiliary contacts arranged between said two fixed outer main contacts;

(b) a plurality of movable contacts each cooperatively related to one of said plurality of fixed contacts; (c) operating means for said plurality of movable contacts including a pivotable driving shaft arranged in the center of said arcuate pattern at right angles to the plane defined by said pattern, said operating means further including a plurality of linkages each having one end operated by said shaft and another end pivotally secured to one of said plurality of movable contacts;

((1) a fixed plate structure arranged at right angles to said shaft and defining a plurality of cam slots, each of said plurality of cam slots being cooperatively engaged by a pivot pin of one of said plurality of linkages situated intermediate said one end and said other end thereof, said plate structure defining at the outer periphery thereof radially inward extending recesses alternating in U-shape and in V-shape; and

(e) a plurality of guide means each integral with one of said plurality of movable contacts and each radially guided in one of said recesses in U-shape.

12. A transfer switch for tapped regulating transformers comprising in combination:

(a) a cylindrical structure substantially of insulating material;

(b) a plurality of fixed contacts supported by said cylindrical structure arranged at the same level along a segment thereof, said plurality of contacts including two fixed outer main contacts and fixed inner auxiliary contacts arranged between said two fixed outer main contacts;

() a plurality of movable contacts each cooperatively related to one of said plurality of fixed contacts;

(d) operating means for said plurality of movable contacts including a pivotable driving shaft coextensive with the axis of said cylindrical structure, a slidesupporting member having a radially inner hub portion mounted on said shaft and a radially outer substantially fork-shaped portion defining a pair of straight spaced parallel guide surfaces, a slide supported by said slide-supporting member and guided by said pair of guide surfaces, a plurality of helical tension springs interconnecting said hub portion of said member and said slide to bias said slide radially inwardly toward said shaft, and a plurality of linkages each having one end pivotally secured to said slide and another end pivotally secured to one of said plurality of movable contacts; and

(e) a fixed plate structure arranged at right angles to said shaft and defining a plurality of cam slots, each of said plurality of cam slots being cooperatively engaged by a pivot pin on one of said plurality of linkages situated intermediate said one end and said other end thereof.

13. A transfer switch for tapped regulating transformers comprising in combination:

(a) a pair of coaxial cylindrical contact supporting 65 structures substantially of insulating material arranged in spaced relation leaving a laterally substantially open cylindrical space therebetween;

(b) a first plurality of fixed contacts supported in an arcuate pattern on the outside of one of said pair of cylindrical structures;

(c) a second plurality of fixed contacts supported in an arcuate pattern on the outside of the other of said pair of cylindrical structures each in registry with one of said first plurality of fixed contacts;

(d) a plurality of movable contact-bridges each 1 1 adapted to cooperate with one of said first plurality of fixed contacts and with one of said second plurality of fixed contacts; and

(e) operating means for said plurality of contactplurality of cam means relatively close to the center thereof and said pair of structures defining a plurality of substantially radial contact-bridge-guiding ways adjacent the periphery thereof for guiding said bridges for moving each of said plurality of contact 5 plurality of contact-bridges, and said operating means bridges selectively radially inward into engagement further including an operating shaft loosely projectwith one of said first plurality and one of said secing at right angles through said pair of disc-shaped ond plurality of fixed contacts and radially outward structures, and a plurality of linkages driven by out of engagement with one of said first plurality said shaft each operatively related to one of said and one of said second plurality of fixed contacts; plurality of contact-bridges and under the control said operating means including a shaft arranged in coaxial relation to and inside of said pair of cylindrical structures, and said operating means further including a plurality of operating linkages driven by of one of said plurality of cam means. 16. A transfer switch for tapped three-phase regulating transformers comprising in combination:

(a) a pair of coaxial cylindrical contact-supporting said shaft, arranged in said cylindrical space prostructures substantially of insulating material arjccting radially outward and each supporting at the ranged in spaced relation;

radially outer end thereof one of said plurality of (b) three relatively narrow rail means angularly dismovable contact-bridges. placed 180 degrees integrating said cylindrical struc- 14. A transfer switch for tapped regulating transformtures into a structural unit leaving the cylindrical ers comprising in combination: space defined between said pair of insulating struc- (a) a pair of coaxial cylindrical contact supporting tures laterally substantially open;

structures substantially of insulating material arranged in spaced relation leaving a laterally substantially open cylindrical space therebetween;

(b) a first plurality of fixed contacts supported in an arcuate pattern on the outside of one of said pair of cylindrical structures;

(0) a second plurality of fixed contacts supported in an arcuate pattern on the outside of the other of 0nd plurality of fixed contacts and for moving said plurality of contact-bridges radially outward out of engagement with one of said first plurality and one of said second plurality of fixed contacts, said oper- (c) a first plurality of fixed contacts supported on the outside of one of said pair of cylindrical structures in each of three sectors thereof bounded by a pair of said rail means;

(d) a second plurality of fixed contacts supported on the outside of the other of said pair of cylindrical structures in each of three sectors thereof bounded by a pair of said rail means;

said pair of cylindrical structures each in registry (e) a plurality of radially movable contact-bridges adwith one of said first plurality of fixed contacts; jacent each of said three sectors of each of said pair (d) operating means for said plurality of contactof cylindrical structures; and

bridges for moving each of said plurality of contact- (f) operating means for said plurality of movable bridges selectively radially inward into engagement contact-bridges including a pair of fixed substantially with one of said first plurality and one of said secdisc-shaped structures arranged in parallel relation within said space at right angles to the axis of said pair of cylindrical structures, each of said pair of disc-shaped structures defining a plurality of cam surfaces in each of the three sectors of said pair of ating means including a shaft arranged in coaxial redisc-shaped plates bounded by a pair of said rail lation to and inside of said pair of cylindrical strucmeans, an operating shaft loosely projecting at right tures, a plurality of operating linkages driven by angles through said pair of disc-shaped structures, said shaft, arranged in said cylindrical space and and a plurality of linkages arranged in each of the each supporting one of said plurality of movable three sectors of said space bounded by a pair of said contact-bridges at the radially outer end thereof, and rail means, said plurality of linkages being under the said operating means further including a plurality of control of both said shaft and of said cam surfaces cam means each operatively related to one of said in each of said three sectors of said pair of discplurality of operating linkages for controlling the shaped plates.

speed of movement thereof. 17. In a transfer switch for tapped regulating trans- 15. A transfer switch for tapped regulating transformformers the combination of:

(a) an upper fixed contact;

( b) a lower fixed contact;

(0) a vertical contact bridge for conductively interconnecting said upper contact and said lower coners comprising in combinaiton:

(a) a pair of coaxial cylindrical contact supporting structures substantially of insulating material arranged in spaced relation leaving a laterally substantialy open cylindrical space therebetween; 5;, tact separable from said upper contact and from said (b) a first plurality of fixed contacts supported in an lower contact;

arcuate pattern on the outside of one Of said pair 1) a pair of superimposed contact-brjdge-operating of cylindrical Structures; toggle-levers, each of said pair of toggle-levers being a Second plurality of fiXed contacts 81119130r ted 111 all pivotally connected with one end thereof to vertically arcuate pattern on the outside of the other of said Spaced registering points of Said Contact bridge. pair of cylindrical structures each in registry with one (e) means for Operating the other ends of a Pair of Sald fi ahty of fixefi contacts; of toggle-levers, said means including a vertical piv- (d) operating means for said plurality of fcontact- Otable Shaft.

bridges for moving each of said plurality 0 contact bridges selectively radially inward into engagement 5 (f) palrf y z ach ffmmmg plvot with one of said first plurality of fixed contacts 0 one 0 Sal palr O togg mtemledl'ate i and one of said second plurality of fixed contacts ends thereof i each of Sand pan of plus having and for moving said plurality of contact-bridges uiWard1PI1etmg ends; and j radially outward out of engagement with one of said (8) tWO P 0f p e pl tes hav ng re glstermg cam first plurality of fixed contacts and one of said secslots P luxtaposed sldes thereof: sald outwardly ond plurality of fixed contacts, said operating means prolectmg ends of 0116 of Said P of P engaging including a pair of substantially disc-shaped struc- Said cam Slots in one P of said tWO Pairs of tures arranged in parallel within said space at right plates, and said outwardly projecting ends of the angles to the axis of said pair of cylindrical strucother of said pair of pins engaging said cam slots in tures, said pair of disc-shaped structures defining a the other pair of said two pairs of plates.

18. In a transfer switch for tapped regulating transformers the combination of (a) an upper fixed contact;

- (b) a lower fixed contact;

(c) a vertical contact-bridge for conductively interconnecting said upper contact and said lower contact separable from said upper contact and from said lower contact;

(d) a superimposed pair of contact-bridge-operating toggle-levers, each of said pair of toggle-levers being pivotally connected with one end thereof to vertically spaced registering points of said contact bridge;

(e) a pair of transverse pins eac-h forming a pivot of one of said pair of toggle-levers intermediate the ends thereof and each of said pair of pins having outwardly projecting ends;

(f) two pairs of parallel plates having registering cam slots on juxtaposed sides thereof, said outwardly projecting ends of one of said pair of pins engaging said cam slots in one pair of said two pairs of plates and said outwardly projecting ends of the other of said pair of pins engaging said cam slots in the other pair of said two pairs of plates; and

(g) means for operating the other ends of said pair of toggle-levers, said operating means including a slide pivotally connected to and spacing said other ends of said pair of toggle-levers, a pivotable slide support, means allowing movement of said slide relative to said slide support, and biasing spring means for said slide interposed between said slide and said slide support.

19. A transfer switch for tapped regulating transformers comprising in combination:

(a) a pair of cylindrical coaxial contact supports substantially of insulating material arranged in spaced relation and leaving a cylindrical laterally substantially open space therebetween;

(b) a first plurality of fixed contacts supported in an arcuate pattern on the outside of one of said pair of contact supports;

(c) a second plurality of fixed contacts supported in an arcuate pattern on the outside of the other of said pair of contact supports each in registry with one of said first plurality of fixed contacts;

(d) a plurality of movable contact-bridges arranged outside of said cylindrical laterally substantially open space each cooperating with one of said first plurality of contacts and with one of said second plurality of contacts;

(e) a plurality of superimposed pairs of toggle-levers arranged inside said cylindrical laterally substantially open space, the constituent toggle-levers of each of said plurality of pairs having ends projecting to the outside of said cylindrical laterally substantially open space and being pivotally connected to vertically spaced registering points on one of said plurality of contact bridges, and the constituent togglelevers of each of said plurality of pairs including a pair of transverse pivot pins having outwardly projecting ends;

(f) two pairs of parallel plates, each pair of said pairs of plates having cam slots on juxtaposed sides thereof engaged by said outwardly projecting ends of one of a pair of said pivot pins; and

(g) means for operating the ends of said plurality of pairs of toggle-levers remote from said plurality of contact bridges, said operating means including a spacing member for spacing superimposed pairs of said toggle levers, a support for said spacing member slidably supporting said spacing member, and a pivotable shaft supporting said support and projecting loosely at right angles across said two pairs of parallel plates.

20. A transfer switch for tapped regulating transformers comprising in combination:

(a) an upper vertical cylindrical contact support substantially of insulating material;

(b) a lower vertical cylindrical contact support substantially of insulating material arranged coaxial to and spaced from said upper contact support to define a gap therebetween encompassing about 360 degrees;

(c) a first plurality of fixed contacts arranged in spaced relation in an arcuate configuration supported by said upper contact support on the outer surface thereof;

(d) a second plurality of fixed contacts arranged in spaced relation in an arcuate configuration supported by said lower contact support on the outer surface thereof, each of said second plurality of fixed contacts being arranged in registry with one of said first plurality of fixed contacts;

(e) a plurality of movable vertical contact bridges arranged radially outwardly beyond said outer surface of said upper contact support and radially outwardly beyond said outer surface of said lower contact support each for conductively interconnecting one of said first plurality of fixed contacts and one of said second plurality of fixed contacts; and

(f) operating means for moving said plurality of contact bridges radially inwardly into engagement with said first plurality of fixed contacts and said second plurality of fixed contacts, said operating means including a shaft arranged coaxially inside said upper contact support and inside said lower contact support, a plurality of linkages operated by said shaft and arranged in the space between said upper contact support and said lower contact support, said plurality of linkages having ends projecting radially outwardly beyond said upper contact support and radially outwardly beyond said lower contact support and through said gap defined between said upper contact support and said lower contact support and tied to said plurality of contact bridges.

21. A transfer switch for tapped regulating transformers comprising in combination:

(a) an upper vertical cylindrical contact support substantially of insulating material;

(b) a lower vertical cylindrical contact support substantially of insulating material arranged coaxial to and spaced from said upper contact support to define a gap therebetween encompassing about 360 degrees;

(c) a first plurality of fixed contacts arranged in spaced relation in an arcuate configuration supported by said upper contact support on the outer surface thereof;

(d) a second plurality of fixed contacts arranged in spaced relation in an arcuate configuration supported by said lower contact support on the outer surface thereof, each of said second plurality of fixed contacts being arranged in registry with one of said first plurality of fixed contacts;

(e) a plurality of movable vertical contact bridges arranged radially outwardly beyond said outer surface of said upper contact support and radially outwardly beyond said outer surface of said lower contact support each for conductively interconnecting one of said first plurality of fixed contacts and one of said second plurality of fixed contacts; and

(f) operating means for moving said plurality of contact bridges radially inwardly into engagement with said first plurality of fixed contacts and with said second plurality of fixed contacts, said operating means including a shaft arranged coaxially inside said upper contact support and inside said lower contact support, a plurality of linkages operated by said shaft and arranged in the space between said upper contact support and said lower contact support, said plurality of linkages having radially outer ends projecting through said gap defined between said upper contact support and said lower contact support and tied to said plurality of contact bridges, and a plurality of fixed cam means each operatively related to one of said plurality of linkages for controlling the movement thereof.

References Cited by the Examiner UNITED STATES PATENTS 6/1954 Jansen 200-6 5/1958 Jansen 20017 

1. A TRANSFER SWITCH FOR TAPPED REGULATING TRANSFORMERS COMPRISING IN COMBINATION: (A) A PLURALITY OF FIXED CONTACTS ARRANGED IN AN ARCUATE PATTERN, SAID PLURALITY OF FIXED CONTACTS INCLUDING TWO FIXED OUTER MAIN CONTACTS AND FIXED INNER AUXILIARY CONTACTS ARRANGED BETWEEN SAID TWO FIXED OUTER MAIN CONTACTS; (B) A PLURALITY OF MOVABLE CONTACTS EACH MOVABLE ALONG A RADIUS OF SAID ARCUATE PATTERN INTO ENGAGEMENT AND OUT OF ENGAGEMENT WITH ONE OF SAID PLURALITY OF FIXED CONTACTS, SAID PLURALITY OF MOVABLE CONTACTS INCLUDING TWO MOVABLE OUTER MAIN CONTACTS EACH COOPERATIVELY RELATED TO ONE OF SAID TWO FIXED OUTER MAIN CONTACTS, AND SAID PLURALITY OF MOVABLE CONTACTS FURTHER INCLUDING MOVABLE INNER AUXILIARY CONTACTS EACH OPERATIVELY RELATED TO ONE OF SAID FIXED INNER AUXILIARY CONTACTS; (C) A PLURALITY OF TOGGLE-LEVERS EACH HAVING ONE END PIVOTALLY CONNECTED TO ONE OF SAID PLURALITY OF MOVABLE CONTACTS AND EACH INCLUDING AN INTERMEDIATE PIVOT PIN SITUATED BETWEEN THE ENDS THEREOF; (D) COMMON MEANS FOR OPERATING THE OTHER END OF EACH OF SAID PLURALITY OF TOGGLE-LEVERS, SAID OPERATING MEANS INCLUDING A PIVOTABLE DRIVING SHAFT ARRANGED IN THE CENTER OF SAID ARCUATE PATTERN AND AT RIGHT ANGLES TO THE PLANE DEFINED BY SAID PATTERN; AND (E) A PLURALITY OF FIXED CAM MEANS EACH COOPERATIVELY ENGAGING SAID GUIDING SAID INTERMEDIATE PIVOT PIN OF ONE OF SAID PLURALITY OF TOGGLE-LEVERS. 